Brake structure for caster wheels



H. P. NIELSEN BRAKE STRUCTURE FOR CASTER WHEELS Dec. 16, 1930.

Filed Feb. 19, 1930 I INVENTOR.

ATTORNEYS.

Pea-med 1)...16, 1930 UNITED STATES PATENT oFFics HANS P. NIELSEN, OI ALAIEDA, CALIFORNIA, ASSIGNOB '10 EAMES COMPANY, OF

SAN FRANCISCO, CALIFORNIA. A CORPORATION OF CALIFORNIA BRAKE STRUCTURE FOR CASTEB WHEELS Befiied for application Serial R0. 87,048, dated January 16, 1928. This application filed February-19,

1930. Serial No. 429,839.

This application is a refile of my application entitled, Brake structure for caster wheels, filed January 16, 1928, Serial No. 247,048.

Thisinvention relates to casters and pariicularly pertains to a brake structure there- It is the principal object of the present invention to provide a generally improved 1 brake for a caster capable of effectively preventing rotation of the wheel. 0 p

In carryin out the invention lnto practice, I provide a brake plate yieldably retained out of contact with the wheel. A cam is provided for cooperation with the brake plate and is capable of forcing the brake plate into contact with the wheel to prevent rotation thereof.

One form which the invention may assume go is exemplified in the following description and illustrated by way of example in the accompanying drawings, in which: Fig. 1 is a perspective view of a caster embodying the preferred form of my invention. Fig. 2 is a sectional view through the fork of the caster showing the springemployed in maintaining the brake plate out of contact with the wheel. Fig. 3 is a central section through the caster showing the braking mechanism.

Fig. 4 is a view in end elevation of the caster with parts in section to more clearly disclose the construction of certain parts.

Referring more particularly to the accompan ing drawings 10 indicates a caster assem 1y. This assembly includes a fork 11 which embraces a wheel 12 of any suitable design. An axle 14 extends laterally between the lower ends of the legs 15 of the fork and the wheel 12 is mounted on this axle. At its upper end the fork 11 is fitted with a spindle 16 or other suitable device for mounting the caster on the bottom of a truck or other ehicle in connection with which casters are 4 employed.

'to the brake The present invention is particularly concerned with a brake mechanism to prevent rotation of the wheel relative to the fork and thus effectively arrest movement of the vehicle upon which the caster is mounted. The brake mechanism referred to comprises a piv otal brake plate 17 arranged between thelegs of the fork 11 above the wheel. At one end this brake plate 17 is formed with a bearing 18 pivotally mounted on a pin 19 extending .17 and is also disposed between the legs 15 of the fork 11. The mounting of the cam is best illustrated in Fig. 4.

Reference being had to this figure it is seen that the cam 21 is provided with a trunnion 22 having a reduced end 23 j ournaled in one leg 15 of the fork 11. A socket 24 is formed'in the other end of the cam co-axially of the trunnion and a pin 25 is threaded through the other leg 15 of the fork 11, and is formed with a reduced portion 26 engaging the socket 24. This mounting of the cam 21 permits it to rotate about its axis. To operate the cam 21, the reduced end 23 of the cam trunnion 22 is squared and an operating lever 27 is secured on this squared portion. Therefore, it is obvious that oscillating movement of this lever 27 will revolve the cam about its axis.

Reference being had to Fig. 2 it will be seen that a coiled spring 28 is wrapped around the pin 25 with one of its ends anchored to the fork 11 and with its other end connected tends to maintain the brake plate 17 out of plate 17. This spring normally v a said cam to cause the same to press t .in its construction b those s allowing the latter to revolve freely. How- 'ever, when the cam is turned to bring its groove '29 out of register with the projection 20 on the brake plate 17, the latter will be pressed tightly mto engagement with the wheel and effectively brake the same.

In operation of the device, it is constructed and assembled as shown in the drawings and mounted on the bottom of a vehicle employwheel embraced thereby, a cam plate pivotally mounted between the legs of the fork and capable of engaging the peri hery of the wheel, spring means constant y tending to maintain the brake plate out of contact with ing casters. The cam 21 is so disposed that it will register with the projection 20, ermitting the s ring 28 to maintain the bra e plate 17 out 0 contact with the wheel, allowing the latter to revolve freely. When desiring to put on the brake, one end of the lever 27 is depressed, throwing the groove 29 in the cam 21 out of register with the rejection 20 on the brake plate 17 and causing the latter to be pressed ti%htly into engagement with the wheel; thus e ectively preventing relative rotation between the wheel and fork.

To release the brake, the end of the lever which has'been de ressed is given an upward movement to revoiire the cam 21. As soon as the rojection 20 re ters with the groove 29 in t e cam, the brafib will be released as the spring 28 will move the projection into onagement with the groove 29 and relatively atch the cam and brake plate together.

From the foregoing it is obvious that I have provided an effective brake mechanism for caster wheels and while I have shown the preferred form of my invention, it is to be understood that various chanlgplsimay be made ed in the art, without de artin om the spirit of the invention as efine in the appended claims. V

, Having thus described my invention, what I claim and desire to secure by Letters Patent is:

' 1. A caster including a fork, a wheel embraced thereby, a pivotal brake member car- 'ried by the fork and adapted to engage the peripheral surface of the wheel, sprin means.

c onstantlytendingto maintain sai brake member out of contact with the wheel, and operative cam means adapted to press said brake member into firm contact with the periphery of the wheel.

2. A caster structure including) a fork, a wheel embraced thereby, a pivotal rake plate adapted to engage the ripheral surface of the wheel, a cam rotata 1y disposed between .the legs of the fork, and a lever for operating e brake plate into contact with the ,wheel.

I us

3. A caster structure including a fork,v a i 

